A new legal hurdle will make it more difficult for parents to get children with special needs into one of Tony Blair's flagship academies.
In a letter to local education authorities, the Department for Education and Skills (DfES) said: "Parents do not have a statutory right to express a preference for the academy."
The revelation is a major embarrassment for the Prime Minister, coming on the day he sought to make it clear his education reforms would not lead to a two-tier system - with a keynote speech aimed at wooing rebel backbenchers to support his plans.
Martin Rogers, co-ordinator of the education think- tank TEN, said: "This letter spells out rather starkly that parents of some of our most vulnerable children have no statutory right to 'choose' an academy. Academies are meant to be the Government's flagship schools for meeting the needs of the disadvantaged."
They are also the model for the new "trust" schools proposed in the Education White Paper - schools which will have opted out of council control and be run independently with a business partner or faith group. Ministers want the majority of schools to opt for "trust" status and Mr Blair has already set a target of 200 academies replacing struggling inner-city schools by 2010.
Mr Rogers added: "In some disadvantaged areas there are already plans for several academies to replace maintained schools so parents of children with special needs will find their right to 'choose' a school increasingly restricted."
Under arrangements for maintained schools, parents must be asked to name the school they would like their child to attend and - if the school turns down the application on the grounds it cannot cope with the child's disability - the local authority must investigate.
If it believes the school is the right place for the child, it will then name the school in the child's special-needs statement - which means the school must take the child. However, if parents want to send their special- needs child to an academy and it refuses, the local authority does not have the power to name the school. Instead, the case will be referred to a resolution service . The Secretary of State can be asked to intervene.
In his letter to local authorities, Ian Coates, head of the special educational needs and disability division at the DfES, said: "Where the academy is of the opinion that the child's attendance at the school would be incompatible with the efficient education of the other children and there are no reasonable steps that could be taken to prevent that incompatability and consequently does not consent to being named in the child's statement, the local authority should not name the academy."
Mr Rogers said: "This illustrates very clearly the importance of having fair admissions arrangements for all children right across every type of school."Reuse content